Question

$C{H}_{3}CH(OH)COOH$ shows:

• A. geometrical isomerism
• B. optical isomerism
• C. both [a] and [b]
• D. none of the above

Answer 1

Answer: (B)

(i) A compound shows geometrical isomerism if it has at least one carbon-carbon double bond and the two groups attached to the same carbon atom are different.
(ii) A compound shows optical isomerism if it has at least one asymmetric or chiral carbon atom and does not have plane of symmetry.
$H-\underset{\stackrel{|}{H}}{\stackrel{\underset{|}{H}}{C}}-\underset{\stackrel{|}{\mathrm{OH}}}{\stackrel{\underset{|}{H}}{C}}\ast -\stackrel{\underset{||}{O}}{C}-OH$
$\because$ The compound has one asymmetric carbon (marked $\ast$) atom.
$\therefore$ It shows optical isomerism.
$\because$ The compound does not have $C=C$.
$\therefore$ It does not show geometrical isomerism.